Where the word 'nonce' comes from as ex-prisoner reveals slang was code word

dailystar.co.uk:

Channel 5 documentary, HMP Wakefield: Evil Behind Bars, has focused on the Yorkshire institution, and in one section highlighted the jail’s large amounts of sex offenders.Containing infamous names including Roy Whiting – who was convicted of abducting and murdering 8 year-old Sarah Payne in 2000 – the so-called 'Monster Mansion' is also home to Robert Maudsley, who has spent more than 30 years locked up.As well as revealing details about life inside, the documentary offered viewers an understanding of labels given to offenders during their time as inmates.Mark, a former inmate, began by explaining that HMP Wakefield carried a reputation for housing prisoners who would typically be held in solitary confinement in other jails.“What prisoners refer to as ‘nonces’, or sex offenders, or people in prison for serious crimes against women and children,” he added.And, Noel ‘Razor’ Smith, who did time at HMP Whitemoor in Cambridgeshire, suggested that HMP Wakefield had been so full of prisoners who had taken part in sex crimes, that a new term had been invented.“Wakefield is where the word ‘nonce’ for sex offender actually originated,” he claimed.Noel explained that this term had been developed because of the risk to sex offenders of being attacked when prisoners were let out of their cells.He continued: “They had a slate board outside the cell with your name and number, and they would put the letters, ‘N.O.N.C.E’ on it, which actually meant ‘not on normal courtyard exercise’.“So when the staff came round to unlock everybody for exercise and let them out, when they saw nonce on the door they would leave them locked up because they knew if they let them out, the other prisoners would attack them.“So it became the universal word for.